Paragraph

I should know this, but where do I comment on a Paragraph post so that it shows up on Farcaster as well as below the post on Paragraph? Is it just any comment on a cast that includes a link to the post? 

Can I publish a cast myself with thoughts on a post and have it show up as a comment somehow?

a fragmented Ethereum can’t scale // product marketing @espressosys // prev marketing work @coinbase @darkblock // 10+ yrs in biz journalism // dad x2 👨‍👦‍👦

Yup any cast with a link to the post shows up!